Enabling AHCI


S

Scott

Following on from recent threads about solid state drives, I
understand that for best performance AHCI should be enabled. So far
as I can see, there are two stages involved.

The enabling of AHCI in the BIOS settings appears to be fairly
straghtforward (with thanks to Gene for getting me into the BIOS).

However, it appears that the registry needs to be edited also - an
area into which I generally fear to tread. According to
http://support.microsoft.com/kb/922976 this should be done before the
BIOS setting is changed.

If the registry edit goes wrong, will this make it impossible to get
back into Windows using the existing BIOS setting (RAID) in order to
do a system restore or will RAID continue to work normally?

Also, does changing the BIOS setting to AHCI affect the E drive, which
is a data drive - not solid state - or is it only the boot drive that
is affected?

Generally, am I making a mistake in attempting this change?

Any thoughts / ideas / guidance welcome.
 
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C

charlie

Following on from recent threads about solid state drives, I
understand that for best performance AHCI should be enabled. So far
as I can see, there are two stages involved.

The enabling of AHCI in the BIOS settings appears to be fairly
straghtforward (with thanks to Gene for getting me into the BIOS).

However, it appears that the registry needs to be edited also - an
area into which I generally fear to tread. According to
http://support.microsoft.com/kb/922976 this should be done before the
BIOS setting is changed.

If the registry edit goes wrong, will this make it impossible to get
back into Windows using the existing BIOS setting (RAID) in order to
do a system restore or will RAID continue to work normally?

Also, does changing the BIOS setting to AHCI affect the E drive, which
is a data drive - not solid state - or is it only the boot drive that
is affected?

Generally, am I making a mistake in attempting this change?

Any thoughts / ideas / guidance welcome.
Changing to AHCI generally does not cause a problem with existing
drives. RAID is another story. Back up everything before you start.
You usually can back up the registry as a separate item from regedit.
 
P

PaulM

"Scott" wrote in message
news:mn4pj8lpirkg6qa6ihnjaufmvu8fpc7mml@4ax.com...
Following on from recent threads about solid state drives, I
understand that for best performance AHCI should be enabled. So far
as I can see, there are two stages involved.
The enabling of AHCI in the BIOS settings appears to be fairly
straghtforward (with thanks to Gene for getting me into the BIOS).
However, it appears that the registry needs to be edited also - an
area into which I generally fear to tread. According to.
http://support.microsoft.com/kb/922976 this should be done before the
BIOS setting is changed.
If the registry edit goes wrong, will this make it impossible to get
back into Windows using the existing BIOS setting (RAID) in order to
do a system restore or will RAID continue to work normally?
Also, does changing the BIOS setting to AHCI affect the E drive, which
is a data drive - not solid state - or is it only the boot drive that
is affected?
Generally, am I making a mistake in attempting this change?
Any thoughts / ideas / guidance welcome.

I have a script here to change the reg setting for you.

http://www.paulsxp.com/forum/viewtopic.php?f=12&t=2372
 
S

Scott

Changing to AHCI generally does not cause a problem with existing
drives. RAID is another story. Back up everything before you start.
You usually can back up the registry as a separate item from regedit.
Thanks for your posting. Of course I would back up but my greater
concern is if the Registry change goes wrong, can I be guaranteed to
get back into Windows at all to reverse the change and restore the
back-up?
 
S

s|b

However, it appears that the registry needs to be edited also - an
area into which I generally fear to tread. According to
http://support.microsoft.com/kb/922976 this should be done before the
BIOS setting is changed.

If the registry edit goes wrong, will this make it impossible to get
back into Windows using the existing BIOS setting (RAID) in order to
do a system restore or will RAID continue to work normally?
Forget about system restore. Use freeware like Macrium Reflect. You can
create a bootable CD-ROM or a bootable flash drive to create and restore
an image of your drive.
Also, does changing the BIOS setting to AHCI affect the E drive, which
is a data drive - not solid state - or is it only the boot drive that
is affected?

Generally, am I making a mistake in attempting this change?
I went ahead and installed this REG-file to enable AHCI.

| Windows Registry Editor Version 5.00
|
| [HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\msahci]
| "Start"=dword:00000000
| "Type"=dword:00000001
| "ErrorControl"=dword:00000003
| "ImagePath"=hex(2):5c,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,\
| 74,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,44,00,52,\
| 00,49,00,56,00,45,00,52,00,53,00,5c,00,6d,00,73,00,61,00,68,00,63,00,69,00,\
| 2e,00,73,00,79,00,73,00,00,00
| "Group"="SCSI Miniport"
| "DriverPackageId"="mshdc.inf_x86_neutral_3f3676f4c0e7d884"

My C: drive is SSD and my D: drive is SATA. The latter was not affected.
AS SSD confirmed AHCI was enabled.

Nothing exploded.
 
S

Scott

Forget about system restore. Use freeware like Macrium Reflect. You can
create a bootable CD-ROM or a bootable flash drive to create and restore
an image of your drive.
I assume the Ghost recovery CD works in the same way.
Also, does changing the BIOS setting to AHCI affect the E drive, which
is a data drive - not solid state - or is it only the boot drive that
is affected?

Generally, am I making a mistake in attempting this change?
I went ahead and installed this REG-file to enable AHCI.

| Windows Registry Editor Version 5.00
|
| [HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\msahci]
| "Start"=dword:00000000
| "Type"=dword:00000001
| "ErrorControl"=dword:00000003
| "ImagePath"=hex(2):5c,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,\
| 74,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,44,00,52,\
| 00,49,00,56,00,45,00,52,00,53,00,5c,00,6d,00,73,00,61,00,68,00,63,00,69,00,\
| 2e,00,73,00,79,00,73,00,00,00
| "Group"="SCSI Miniport"
| "DriverPackageId"="mshdc.inf_x86_neutral_3f3676f4c0e7d884"

My C: drive is SSD and my D: drive is SATA. The latter was not affected.
AS SSD confirmed AHCI was enabled.
If I am following this correctly, I should edit the registry first.
Then I should restart the computer and go direct to the BIOS settings.
There I should change the appropriate setting from RAID to ACHI. Then
start Windows.

If this is successful, mission accomplished. If unsuccessful I should
restart from the recovery disc and return the registry to its earlier
settings.

Am I cooking on gas?
 
S

s|b

If I am following this correctly, I should edit the registry first.
Then I should restart the computer and go direct to the BIOS settings.
There I should change the appropriate setting from RAID to ACHI. Then
start Windows.
Yes.

There's more information to be found in this thread:
If this is successful, mission accomplished. If unsuccessful I should
restart from the recovery disc and return the registry to its earlier
settings.
What recovery disk? Are you referring to Macrium Reflect?
 
S

Scott

Yes.

There's more information to be found in this thread:


What recovery disk? Are you referring to Macrium Reflect?
I was thinking of the Symantec (Norton) recovery disc, on the basis
that it is set up - and tested - already.
 
S

s|b

I was thinking of the Symantec (Norton) recovery disc, on the basis
that it is set up - and tested - already.
I don't know how that works. I used to use Norton Ghost, but I switched
to Macrium Reflect (Free) a while ago. It's the same principle: you can
create an image of your disk/partition(s) and you don't need a separate
program like Ghost Explorer to explore a Macrium Reflect image. You can
then restore that image by using a bootable CD-ROM or flash drive. To be
safe, you should also copy the image to an external hdd.

But if you are used to Symantec software you can use this as well. I'm
pretty sure you won't need it.
 
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S

Scott

I don't know how that works. I used to use Norton Ghost, but I switched
to Macrium Reflect (Free) a while ago. It's the same principle: you can
create an image of your disk/partition(s) and you don't need a separate
program like Ghost Explorer to explore a Macrium Reflect image. You can
then restore that image by using a bootable CD-ROM or flash drive. To be
safe, you should also copy the image to an external hdd.

But if you are used to Symantec software you can use this as well. I'm
pretty sure you won't need it.
Thanks for all your assistance. If Macrium is free, there is nothing
to stop me making a Macrium CD in case the Norton one fails.
 
P

Paul

Scott said:
Thanks for all your assistance. If Macrium is free, there is nothing
to stop me making a Macrium CD in case the Norton one fails.
Try here.

http://www.macrium.com/reflectfree.asp

Most of that (relatively small) download, consists of a Linux boot
CD with dedicated Macrium GUI interface. You boot the Linux CD and
the Macrium interface will guide you to select the backup file you
made. Then you can restore. (No part of Linux is visible to you,
so there are no Linux wizmo commands you can use or anything. You're
insulated from the Linux part.)

I walk through the whole process, of backup and restore, in these
pictures taken of a VM running the software. Click on the image,
to zoom in. This is how I tested that it works.

http://img31.imageshack.us/img31/4512/macriumrestore.gif

Macrium has a second option, where you end up making something like
a WinPE CD, but that option involved a 1GB download from Microsoft
to get WAIK. And for most people with regular desktop setups,
is unnecessary. Try the Linux option first, which is built right in.
The reason they have two solutions, is in case one of them doesn't
work for you. For example, if you had a RAID setup, maybe
WinPE with custom drivers would be the way to go. Linux wouldn't
have drivers for everything, just the common cases (IDE, AHCI).

It helps to test, that the recovery CD, works ahead of time.
Don't burn the CD, then need to do a restore, then, figure out
the CD doesn't work. At least test that it boots to the
recovery GUI and asks for a file to restore from.

Paul
 
S

Scott

However, it appears that the registry needs to be edited also - an
area into which I generally fear to tread. According to
http://support.microsoft.com/kb/922976 this should be done before the
BIOS setting is changed.

If the registry edit goes wrong, will this make it impossible to get
back into Windows using the existing BIOS setting (RAID) in order to
do a system restore or will RAID continue to work normally?
Forget about system restore. Use freeware like Macrium Reflect. You can
create a bootable CD-ROM or a bootable flash drive to create and restore
an image of your drive.
Also, does changing the BIOS setting to AHCI affect the E drive, which
is a data drive - not solid state - or is it only the boot drive that
is affected?

Generally, am I making a mistake in attempting this change?
I went ahead and installed this REG-file to enable AHCI.

| Windows Registry Editor Version 5.00
|
| [HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\msahci]
| "Start"=dword:00000000
| "Type"=dword:00000001
| "ErrorControl"=dword:00000003
| "ImagePath"=hex(2):5c,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,\
| 74,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,44,00,52,\
| 00,49,00,56,00,45,00,52,00,53,00,5c,00,6d,00,73,00,61,00,68,00,63,00,69,00,\
| 2e,00,73,00,79,00,73,00,00,00
| "Group"="SCSI Miniport"
| "DriverPackageId"="mshdc.inf_x86_neutral_3f3676f4c0e7d884"

My C: drive is SSD and my D: drive is SATA. The latter was not affected.
AS SSD confirmed AHCI was enabled.

Nothing exploded.
Thank you very much for your assistance. At first I was unable to
change the registry setting until I realised (as I should have
realised in the first place) that I needed to be logged in as the
administrator. I then successfully changed the value to '0' and had
no difficulty changing the BIOS setting to 'ACHI' and restarting
Windows.

However, I am now getting a message that my system does not support
SATA 6Gb/s (SATA 3). Should I be worried about this? Would SATA 3
require a new motherboard?

If all that is involved is that I am not getting maximum speed, I am
perfectly happy with what I am getting at present so I would not want
to spend any serious money!
 
S

s|b

Thank you very much for your assistance. At first I was unable to
change the registry setting until I realised (as I should have
realised in the first place) that I needed to be logged in as the
administrator. I then successfully changed the value to '0' and had
no difficulty changing the BIOS setting to 'ACHI' and restarting
Windows.
Have you checked if AHCI is activated? You can do this with AS SSD. It's
freeware and portable, so nothing has to be installed. Just unzip and
doubleclick on the EXE.

However, I am now getting a message that my system does not support
SATA 6Gb/s (SATA 3). Should I be worried about this? Would SATA 3
require a new motherboard?
What motherboard do you have now?

Wikipedia teaches me that SATA 3 Gb/s and 6 Gb/s are compatible:
<https://en.wikipedia.org/wiki/Serial_ATA#SATA_3_Gbit.2Fs_and_SATA_6_Gbit.2Fs>

<quote>

SATA 3 Gbit/s and SATA 6 Gbit/s are compatible with each other. Most
devices which are only SATA 3 Gbit/s can connect with devices that are
SATA 6 Gbit/s, and vice-versa, though obviously SATA 3 Gbit/s devices
only connect with SATA 6 Gbit/s devices at the slower 3 Gbit/s speed.

</quote>

And...

| SATA 1.0 = SATA 150 = 1.5GB/s
| SATA 2.0 = SATA 300 = 3GB/s
| SATA 3.0 = SATA 600 = 6GB/s
If all that is involved is that I am not getting maximum speed, I am
perfectly happy with what I am getting at present so I would not want
to spend any serious money!
It should work. Do you get that message every time?
 
S

Scott

Have you checked if AHCI is activated? You can do this with AS SSD. It's
freeware and portable, so nothing has to be installed. Just unzip and
doubleclick on the EXE.
Samsung Magicial says it is.
I tried this (in German!) and it seemed to be benchmarking data.
What motherboard do you have now?
Not sure how to find out, but it's an HP Pavilion computer.
Wikipedia teaches me that SATA 3 Gb/s and 6 Gb/s are compatible:
<https://en.wikipedia.org/wiki/Serial_ATA#SATA_3_Gbit.2Fs_and_SATA_6_Gbit.2Fs>

<quote>

SATA 3 Gbit/s and SATA 6 Gbit/s are compatible with each other. Most
devices which are only SATA 3 Gbit/s can connect with devices that are
SATA 6 Gbit/s, and vice-versa, though obviously SATA 3 Gbit/s devices
only connect with SATA 6 Gbit/s devices at the slower 3 Gbit/s speed.

</quote>
I think that's exactly what is happening. It's running okay but at
SATA 2 speed rather than SATA 3 speed (which is probably not an issue)
And...

| SATA 1.0 = SATA 150 = 1.5GB/s
| SATA 2.0 = SATA 300 = 3GB/s
| SATA 3.0 = SATA 600 = 6GB/s


It should work. Do you get that message every time?
I misled you when I suggested it was a message. What happened is that
when I looked at Samsung Magician it showed (1) AHCI activated and (2)
SATA 2 only (no SATA 3).

I suspect the difference is of no importance for me, but I just
wondered if getting SATA 3 involves a new motherboard or can the
controller be replaced?

Thanks again for your help. It was you who encouraged me to proceed
when others (not here) suggested I should leave well alone!
 
C

charlie

Samsung Magicial says it is.

I tried this (in German!) and it seemed to be benchmarking data.

Not sure how to find out, but it's an HP Pavilion computer.

I think that's exactly what is happening. It's running okay but at
SATA 2 speed rather than SATA 3 speed (which is probably not an issue)

I misled you when I suggested it was a message. What happened is that
when I looked at Samsung Magician it showed (1) AHCI activated and (2)
SATA 2 only (no SATA 3).

I suspect the difference is of no importance for me, but I just
wondered if getting SATA 3 involves a new motherboard or can the
controller be replaced?

Thanks again for your help. It was you who encouraged me to proceed
when others (not here) suggested I should leave well alone!
If all else fails, and you just have to have SATA 3, there are adapters
available. A complication can be the boot drive, and loading a driver to
use the add on SATA adapter. Such an adapter can have on board firmware
that gets around this, by having the firmware run when BIOS is still
active. (Assuming your BIOS will support such things.)
It's kinda the same thing as BIOS initializing the video card..
 
S

Scott

Should read Samsung Magician.
[snip]

If all else fails, and you just have to have SATA 3, there are adapters
available. A complication can be the boot drive, and loading a driver to
use the add on SATA adapter. Such an adapter can have on board firmware
that gets around this, by having the firmware run when BIOS is still
active. (Assuming your BIOS will support such things.)
It's kinda the same thing as BIOS initializing the video card..
Thanks. It sounds to me that since the purpose of the SSD was to act
as the boot drive I would be asking for trouble to try to add adapters
at that stage. I don't see any great need as the speed should already
be much faster than the previous hard drive.
 
P

Paul

Scott said:
I misled you when I suggested it was a message. What happened is that
when I looked at Samsung Magician it showed (1) AHCI activated and (2)
SATA 2 only (no SATA 3).

I suspect the difference is of no importance for me, but I just
wondered if getting SATA 3 involves a new motherboard or can the
controller be replaced?

Thanks again for your help. It was you who encouraged me to proceed
when others (not here) suggested I should leave well alone!
For hard drives, it makes no difference. Yes, bursting data to the
small cache RAM on the hard drive controller board, works faster
at SATA III rates. But when it comes to sustained transfers (doing a
backup), the transfer is limited by the speed of the head to disk
platter interface.

With an SSD, it's different. Some of those can do 500MB/sec over SATA III
on a continuous basis. And if you wanted to impress your friends, you'd
get an add-in card to run that SSD. Getting only 200MB/sec using
some lesser flavor of SATA, wouldn't live up to the performance
billing of the SSD drive. (It would still feel fast, either way.)

The problem right now, is finding such a SATA III card that has good reviews.
I haven't been able to find a SATA III plug-in PCI Express card
with good reviews. For some people, they work, for others, nothing
but problems. Whether all the problems are "finger problems", I
don't know. I just consider it strange that at least one quality
product has not come along.

This is an example of an add-in card for a desktop computer.
The card is low-profile, meaning it fits in a "small" desktop.
This also comes with two faceplates, so the card can be
installed in a regular profile computer, or a low profile computer.
Dell has sold some desktops, where only low-profile cards fit.
This card also has an x4 PCI Express connector. You need to check
the motherboard, for a spare x4, x8, or x16 sized slot. This card
won't fit in an x1 slot, and I've selected a card like this on purpose.
It's to guarantee at least one SATA III port will run full rate
for you. I think this might be based on Marvell 9235, but in
any case, you'd definitely want to find a review site with
benchmarks, before buying it. The Marvell 9128 is limited to
300MB/sec, and we wouldn't want a repeat of that. Checking for
a benchmark for the card, is to avoid unpleasant surprises (i.e.
spend $50+, then find out it is no faster). To benchmark the
Marvell 9235 properly, someone has to combine it with a 500MB/sec
SSD for testing. Then run the RocketRaid in JBOD (meaning, even
a RAID card, can run single hard drives in a one-at-a-time mode).

http://www.newegg.com/Product/Product.aspx?Item=N82E16816115114

Not all desktop computers, have an excess of "good" add-in card slots.
A typical cheesy computer, has one x16 slot (for the video card), and
three x1 slots (for things like TV tuners). You'd want a machine with
two x16 slots, or x16 + x4, or some mixture of useful slots. And not
all computers (as is usual for the computing industry), are set up
for every possible addition.

This is one of the reasons, my current motherboard has two x16 slots.
I stick a mediocre video card in one slot, but the second slot
is available for "experiments", including projects like adding that
SATA III card.

As another example of the trickery involved, here is a motherboard
with two x16 slots. But the left-most large red slot, is actually
wired x4. So this system is actually x16 (white) plus x4 (red).
And the two x1 slots would be suited for TV tuners, or other
lower bandwidth stuff. You have to know the architecture fairly well,
look at the chips (check for bifurcation chips), to understand
what you're really getting. And a pre-build computer, they're
not likely to give you that nice, second, red slot for your
add-in SATA III card.

http://www.amazon.com/Biostar-LGA1155-Chipset-Motherboard-TZ77MXE/dp/B007RUG7I0/ref=sr_1_1?ie=UTF8&qid=1363131927&sr=8-1&keywords=TZ77MXE

There's a lot of dishonesty in the computer industry. I was shocked,
shocked I tell you, to find out my 4GB/sec PCI Express slots, can't
even do 2GB/sec. Someone did a theoretical calculation, and
based on max packet size used in the design of my motherboard
chipset, determined it can't actually do 4GB/sec. I'm not
likely to run into a problem because of that, but if I
spend $1000 on an Areca RAID controller, I have to think
twice before I purchase it. Run of the mill "good" RAID
cards, can be limited by the IOP on the card, to around
800MB/sec. As I/O Processor chips improve, eventually
the cards become slot-limited (by crappy chipset designs
like the one my motherboard uses). And it only gets worse,
when the slots promise to have 8GB/sec or higher - you know
they can't possibly deliver those speeds in the real
world. Just waiting for someone to do the calc...

This is not a big deal. The point is, analysis needs to be
done, for any computer addition, to understand what is
possible - or why, the thing you purchased, didn't pan out.
We're still waiting for an explanation of why the Marvell
9128 only does 300MB/sec. Don't know why, about that one.
There have been a few driver releases for that one, too.
You catch issues like that, by finding a benchmark review
that was done using a 500MB/sec SSD. If someone uses
a 200MB/sec SSD to test a 500MB/sec RAID card, you learn
nothing that way. Many reviewers don't sweat the details
when they review. That's what makes it hard to find
good review info.

Paul
 
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G

Gene E. Bloch

Thanks for all your assistance. If Macrium is free, there is nothing
to stop me making a Macrium CD in case the Norton one fails.
To be explicit: the Macrium recovery CD will let you restore a
previously-made Macrium backup to your hard drive.

I have the paid Macrium, and I don't think the recovery CD lets you get
into a shell to make registry changes. I can be wrong , of course.

Obviously, given the time since your post (I was out of reach of Usenet
for a few days), you may be already set up.
 
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